The development and biology of bradyzoites of toxoplasma gondii

Weiss, Louis M.; Kim, Kami

doi:10.2741/weiss

Cited by 212 publications

(210 citation statements)

References 129 publications

(68 reference statements)

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“…Culture of treated virulent strains in a murine macrophagelike cell line (RAW 264.7) stimulated to produce the parasiticidal molecule, NO, initiated induction of the bradyzoite-specific marker BAG1, which was significantly increased (62% rise in HSP70-reduced RH strain; 75% in HSP70-reduced ENT strain) compared with expression in untreated virulent parasites. No significant effects were observed as a result of HSP70 inhibition in avirulent strains, though the trend was for reduced stage conversion, which would fit with the role of HSP70 in stage conversion of avirulent T. gondii described by Weiss and Kim (26).…”

Section: Discussionsupporting

confidence: 60%

Heat Shock Protein 70 Is a Potential Virulence Factor in MurineToxoplasmaInfection Via Immunomodulation of Host NF-κB and Nitric Oxide

Dobbin

Smith

Johnson

2002

The Journal of Immunology

106

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Section: Discussionsupporting

confidence: 60%

Heat Shock Protein 70 Is a Potential Virulence Factor in MurineToxoplasmaInfection Via Immunomodulation of Host NF-κB and Nitric Oxide

Dobbin

Smith

Johnson

2002

The Journal of Immunology

106

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“…The conversion of some tachyzoites into bradyzoites, which eventually form intracellular tissue cysts in parenchymatous but not in lymphatic organs, is not initiated before day 6 p.i. Moreover, the cyst wall may prevent the efflux or transport of secreted Ag into the host cell cytoplasm where the MHC class I processing pathway is located, whereas the parasitophorous membrane allows the efflux of small molecules between 1.3 and 1.9 kDa from the vacuolar space into the host cell cytoplasm (28,29).…”

Section: Discussionmentioning

confidence: 99%

The Induction and Kinetics of Antigen-Specific CD8 T Cells Are Defined by the Stage Specificity and Compartmentalization of the Antigen in Murine Toxoplasmosis

Kwok

Lütjen

Soltek

et al. 2003

The Journal of Immunology

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Toxoplasma gondii forms different life stages, fast-replicating tachyzoites and slow-growing bradyzoites, in mammalian hosts. CD8 T cells are of crucial importance in toxoplasmosis, but it is unknown which parasite stage is recognized by CD8 T cells. To analyze stage-specific CD8 T cell responses, we generated various recombinant Toxoplasma gondii expressing the heterologous Ag β-galactosidase (β-gal) and studied whether 1) secreted or cytoplasmic Ags and 2) tachyzoites or bradyzoites, which persist intracerebrally, induce CD8 T cells. We monitored the frequencies and kinetics of β-gal-specific CD8 T cells in infected mice by MHC class I tetramer staining. Upon oral infection of B6C (H-2bxd) mice, only β-gal-secreting tachyzoites induced β-gal-specific CD8 T cells. However, upon secondary infection of mice that had received a primary infection with tachyzoites secreting β-gal, β-gal-secreting tachyzoites and bradyzoites transiently increased the frequency of intracerebral β-gal-specific CD8 T cells. Frequencies of splenic and cerebral β-gal-specific CD8 T cells peaked at day 23 after infection, thereafter persisting at high levels in the brain but declining in the spleen. Splenic and cerebral β-gal-specific CD8 T cells produced IFN-γ and were cytolytic upon specific restimulation. Thus, compartmentalization and stage specificity of an Ag determine the induction of CD8 T cells in toxoplasmosis.

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“…Some of these components have been characterised previously by monoclonal antibodies, which have in part facilitated investigations of the tachyzoite/bradyzoite differentiation [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

The role of stage-specific oligonucleotide primers in providing effective laboratory support for the molecular diagnosis of reactivated Toxoplasma gondii encephalitis in patients with AIDS

Contini¹,

Cultrera

Seraceni³

et al. 2002

Journal of Medical Microbiology

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The switch from bradyzoites to tachyzoites is the fundamental pathogenic event that leads to Toxoplasma gondii encephalitis (TE) in patients with AIDS. Distinction between these stages is difficult, particularly when specific treatment has been started. A new approach consisting of a nested PCR (n-PCR) assay was performed on cerebrospinal fluid (CSF) specimens collected from AIDS patients with TE before or after antiparasitic therapy was initiated, to assess the efficacy of primer sets which amplify target sequences expressed on bradyzoites (SAG4 and MAG1), tachyzoites (SAG1) or both stages (B1) of T. gondii. CSF specimens were obtained from 46 patients with AIDS, of whom 27 had TE (16 first episode, 11 relapse) and 19 had other AIDS-related brain lesions (AIDS-OBL) in the absence of TE. CSF specimens from 26 HIV-negative and immunocompetent patients were also checked. All samples were tested with different primer pairs targeting the B1, SAG-1, SAG-4 and MAG-1 genes. With B1, 75% of patients with first episodes of TE were positive, compared with 36.3% of those with relapse of TE and 5.2% of those with AIDS-OLB. The SAG1 gene yielded positive values in 28.7% and 45.4% of patients with first episodes of TE or relapse of TE, respectively, and in none of the controls. With the SAG4 and MAG1 genes, 72.7% of patients with relapse of TE were detected, compared with 25% of patients with first episodes of TE and 5.2% with AIDS-OLB. None of the HIV-negative subjects showed positive PCR reactions. These results demonstrate that specific primers for the genes SAG4, MAG1 and SAG1 may be useful in AIDS patients with relapse of TE, in whom the use of PCR targeting the B1 gene may fail to detect DNA, especially when prophylaxis or treatment has been started.

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The development and biology of bradyzoites of toxoplasma gondii

Cited by 212 publications

References 129 publications

Heat Shock Protein 70 Is a Potential Virulence Factor in MurineToxoplasmaInfection Via Immunomodulation of Host NF-κB and Nitric Oxide

Heat Shock Protein 70 Is a Potential Virulence Factor in MurineToxoplasmaInfection Via Immunomodulation of Host NF-κB and Nitric Oxide

The Induction and Kinetics of Antigen-Specific CD8 T Cells Are Defined by the Stage Specificity and Compartmentalization of the Antigen in Murine Toxoplasmosis

The role of stage-specific oligonucleotide primers in providing effective laboratory support for the molecular diagnosis of reactivated Toxoplasma gondii encephalitis in patients with AIDS

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